GaAs-AlGaAs heterojunction solar cells with increased open-circuit voltage
- Eindhoven Univ. of Technology (Netherlands)
In order to reduce the dark current, the authors studied the incorporation of AlGaAs layers at the junction of GaAs solar cells. According to Shockley`s diode model, the dark current is reduced in case the junction is made of wide bandgap material. However, the GaAs-AlGaAs interfaces form a potential barrier for the generated carriers, which degrades the collection efficiency and sets a limit to the Al concentration. A set of homojunction cells, GaAs and Al{sub 0.1}Ga{sub 0.9}As, and heterojunction cells, with Al concentration of 5, 10 and 15%, as well as a cell with quantum wells have been fabricated. For the characterization, the authors measured dark current, I-V curve under illumination, temperature dependence of the short-circuit current, spectral response and the emission spectra. Compared to the GaAs cell the heterojunction cells reveal a higher open-circuit voltage, due to the reduced dark current. The 5% heterojunction cell showed only a small degradation of the short-circuit current, and relative to the GaAs cell the efficiency was enhanced by 7%. In case of the MQW cell and the 10 and 15% heterojunction cells the reduction of the short-circuit current was more extreme and the advantage of the higher open-circuit voltage was by far compensated, resulting in a reduced efficiency compared to the GaAs cell.
- OSTI ID:
- 191160
- Report Number(s):
- CONF-941203-; ISBN 0-7803-1459-X; TRN: IM9610%%161
- Resource Relation:
- Conference: 1. world conference on photovoltaic energy conversion, Waikoloa, HI (United States), 5-9 Dec 1994; Other Information: PBD: 1994; Related Information: Is Part Of 1994 IEEE first world conference on photovoltaic energy conversion: Conference record of the twenty-fourth IEEE photovoltaic specialists conference -- 1994. Volume 2; PB: 1268 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Neutron irradiation effects on AlGaAs/GaAs heterojunction bipolar transistors
Semi-Analytical Simulation and Optimization of AlGaAs/GaAs p-i-n Quantum Well Solar Cell